| Basics of ColocationServer colocation is usually for | | | | have been made to the LILO configuration |
| those who own their own server hardware and | | | | remember to run "/sbin/lilo -v" and ensure there |
| require complete control over the server | | | | are no errors.Also make sure the kernel "works" |
| configuration. Colocation specialists will house and | | | | properly with the hardware. This is especially true |
| connect a server you own, to a fast internet | | | | if have compiled the kernel yourself or are using |
| connection, usually in a secure datacentre, with 24 | | | | specialist hardware.Make sure the server "Auto |
| 7 support.It is important to choose a colocation | | | | Powers" onMost colocation facilities provide an |
| provider that either has their own data center or | | | | auto power cycler from a web interface. |
| has a presence in one of the leading "data hotels." | | | | However this can fail if the machine does not |
| World Class data centres are located in major | | | | auto power back up (requiring the intervention of |
| industrial cities (New York, London, Frankfurt for | | | | a techie). Most server BIOS's are equipped with |
| example). Here they are able to take advantage | | | | either "OFF", "LAST STATE" or "ALWAYS ON". In |
| of the convergence of high capacity network | | | | this case you will require "ALWAYS ON." it is |
| connectivity that occurs in a major commercial | | | | possible to hack cheaper ATX motherboards to |
| centre. For instance fibre, and metrolinks and ease | | | | be "ALWAYS ON" but it is better to consider a |
| of connection to major Points of Presence (POPS) | | | | more expensive motherboard.Properly Configured |
| to the major telco's. For this reason only a very | | | | NetworkMake sure you configure the network |
| few of the leading ISP's or colocation specialist | | | | addresses, DNS server and gateways properly |
| operate their own dedicated centre's due to the | | | | prior to delivery of the dedicated server. This |
| costs of providing remote connectivity, redundant | | | | information will have been provided in advance by |
| power sources, air conditioning and filtered clean | | | | the colocation provider. Also make sure you can |
| air.Also not all internet connections are equal. You | | | | get back into the server remotely by having the |
| really need to enquire if your colocation specialist | | | | SSHD daemon running (telnet is not |
| is "multihomed" using the BGP protocol by having | | | | secure).OpenSSH is shipped with all the main Linux |
| at least two connections to Tier One providers. | | | | distributions. You might wish to consider |
| Tier One providers are very large ISP's or Telco's | | | | configuring SSH (usually done in /etc/sshd |
| who operate their own fibre links and networks | | | | sshd_config) to work with Protocol2 only, disable |
| without having to operate traffic (or transit) over | | | | root logins (or only allow public key exchanges |
| another ISP's network. An example of a Tier One | | | | with the `without-password` option) and to turn |
| provider would be Level3 communications.In | | | | off X11 forwarding as this is not required on a |
| addition to Tier One connections, the colocation | | | | production server.Many servers have multiple |
| specialist should have peering arrangement's at | | | | ethernet connectors, so it an be helpful, if you are |
| major exchange point's such as LINX. A peering | | | | not using the second interface to either mask it |
| point is where a number of ISP's arrange to | | | | off with tape or label the correct ethernet device. |
| "meet up" to exchange traffic between each | | | | Set up a Serial ConsoleThis is sometimes called |
| other rather than pay for transit over someone | | | | "out of band" management. Quite often a |
| else's network. In a way they are "cutting out the | | | | colocation provider will have a serial terminal on |
| middleman!" This not only improves redundancy | | | | site. This is basically a server itself but with loads |
| but also reduces latency; people will be able to | | | | of serial ports. This enables you to connect to |
| access the websites and content hosted on your | | | | your server if the network has failed to your |
| colocated server much faster if you colo host is | | | | server for any reason.The most common serial |
| well peered.Quite often a web host or Colocation | | | | port settings are 9600 8n1 (we do not |
| ISP will negotiate many peering arrangements | | | | recommend running it a faster speed). If you are |
| with other ISP's with whom they are exchanging | | | | running a Red Hat Linux server serial console |
| a lot of traffic. Not only does this give them more | | | | access is usually configured in "/etc/inittab." Try |
| resilience, but it also reduces their own transit | | | | inserting the line below:co:23456:respawn:/sbin |
| costs with the Tier One providers enabling them | | | | agetty ttyS0 9600 vt100Cooling |
| to offer more competitive data transfer | | | | ConsiderationsServers run pretty hot mainly due |
| pricing.Latency is particularly important when it | | | | to modern processors. Even in a fully air |
| comes to game server hosting and colocation. | | | | conditioned environment. It will pay you look into |
| Quite often an ISP specialising in games hosting will | | | | cooling. A lot will depend on rack density however |
| give you an IP address for you to test ping times | | | | this is one more reason why you should consider |
| and carry out traceroutes.Hardware | | | | a rack optimised server, as the air cooling in a |
| ChoicesServer housing costs in London or New | | | | colocated environment should have been taken |
| York can be expensive. Not suprisingly your | | | | into consideration. You can also familiarise with the |
| hardware should be "rack optimized." Colocation is | | | | chipset architecture of your motherboard and |
| usually priced "per U." A "U" is 1.75 inches (or 4.44 | | | | consider setting up "sensors." You can then |
| cms). So rack servers, unlike desktop machines | | | | monitor the temperature of your CPU and |
| are long and flat. Data Centre's also employ | | | | motherboard and graph it using MRTG. |
| different types Rack Cabinets which are typically | | | | Cheap Colocation ProvidersWell apart from us |
| 42U in height, enough to house 42 1U servers | | | | that is! However the following London based |
| though some of this space is used to accomodate | | | | colocation providers come highly recommended. In |
| switches, cabling. Often some space is left free to | | | | other words, they are in demand, know what |
| allow for efficient air distribution in the cabinet.It's | | | | they are doing and possess "clue."Bogons - - |
| often worth liasing with your colo specialists over | | | | Based in Telehouse, but they may only usually |
| the choice of the physical hardware and especially | | | | Sun Netra servers.Black Cat Networks - - Based |
| the case and rack mounting. The colocation | | | | in Redbus Harbour Exchange.Jump Networks - - |
| specialist will know which brands work in their | | | | Also based in Telehouse North, |
| racks. Personally I have found Dell Rack Optimized | | | | Docklands.Additional ThoughtsYou may wish to |
| Servers and rail kits the quickest and easiest to | | | | consider disc or hard drive redundancy. Although |
| rail up.So you have decided on the hardware, and | | | | the "MTF" or Mean Time to Failure" quoted by |
| you are about to ship your server to the remote | | | | hard drive manufacturers is impressive, hard drive |
| colocation data centre. Bear in mind your server | | | | failure, especially IDE failure happens depressingly |
| will shortly be hundreds of miles away, indeed if | | | | often. With advent of S-ATA drives there is really |
| you are in the USA, it might even be few hours | | | | no excuse, expecially if your are on a budget. You |
| flight away so there are a few technical points to | | | | should consider cheap S-ATA drives (if you |
| consider before the machine is boxed, shipped | | | | cannot afford SCSI) with Linux software RAID. |
| and colocated.Make sure the Operating System | | | | Modern Linux distributions come with tools to |
| rebootsAll colocated dedicated servers run | | | | administer and monitor the performance of |
| "headless." This means without the use of a | | | | software RAID arrays.It can be helpful to duty |
| keyboard or monitor attached. Therefore you will | | | | technicians if all the main power lights are working. |
| need to ensure that the servers gets past the | | | | The power light, hard drive activity light and |
| BIOS screen and boots the desired kernel without | | | | network light can be very useful. It goes without |
| having to press any keys. It might be possible to | | | | saying that the server should be correctly labelled |
| set the BIOS on your dedicated server to stop | | | | at the front with it's hostname and IP address so |
| on "no errors."If your are running Linux the kernel | | | | it can be identified quickly.Paul Lee has over six |
| you will need to ensure the correct kernel is | | | | years experience in the web hosting industry and |
| booted without intervention. This is usually | | | | was formerly Senior System Administrator with |
| determined by the configuration on /etc/grub.conf | | | | Limited. He currently lives and works in London |
| if the GRUB boot loader is used, or /etc/lilo.conf if | | | | and runs his own consultancy and hosting |
| the LILO boot loader is used. After any changes | | | | company Weycrest. |